What: Once a new block has been created, it is propagated to the entire network. According the paper ‘Information propagation in the bitcoin network.’
by Decker and Wattenhofer the mean time for a node to see a block is 12.6 seconds, after 40 seconds 95% of the nodes see the block.
Bitcoin’s blockchain throughput is measured by the number of transactions per second that it can support. Transactions/Block is Bitcoin’s current block capacity and average transaction size:
Transactions/Block = Bitcoin capacity /average Transaction size
Transactions/Block * Blocks/second (Inverse of Block interval) = Network Throughput
Bitcoin’s current Block capacity (2018) is 1MB for a Block interval of ~10 min. With an average transaction size of ~540 bytes, the Bitcoin network currently processes ~1950 transactions per Block, which is ~3 transactions per second (TPS).
You can view a history of Bitcoin propagation rates (blocks and transactions) here: http://bitcoinstats.com/network/propagation/
References:
https://dsn.tm.kit.edu/bitcoin/videos.html
https://www.tik.ee.ethz.ch/file/49318d3f56c1d525aabf7fda78b23fc0/P2P2013_041.pdf
https://medium.com/coinmonks/block-propagation-scaling-and-adoption-maturing-blockchains-99218260b7b8